The present invention relates to an electron beam device in which a plurality of electron emission portions are formed on a substrate, an image forming apparatus in which an image forming member is formed opposite to the electron emission portions and a method of manufacturing those devices.
Up to now, as the electron emitting elements, there have been known the two kinds of a hot cathode element and a cold cathode element. As the cold cathode element of those elements, there have been known, for example, a surface conduction type electron emission element, a field emission element (hereinafter referred to as xe2x80x9cFlE typexe2x80x9d), a metal/insulating layer/metal type emission element (hereinafter referred to as xe2x80x9cMIM typexe2x80x9d), etc.
As the surface conduction type electron emission elements, there have been known, for example, an example disclosed in Radio Eng. Electron Phys., 10, 1290 (1965) by M. I. Elinson, or other examples which will be described later.
The surface conduction type electron emission element utilizes a phenomenon in which electron emission occurs by allowing a current to flow into a small-area thin film formed on a substrate in parallel to a film surface. As the surface conduction type electron emission element, there have been reported a surface conduction type electron emission element using an SiO2 thin film by the above-mentioned Elinson and others, a surface conduction type electron emission element using an Au thin film [G. Dittmer: xe2x80x9cThin Solid Filmsxe2x80x9d, 9,317 (1972)], a surface conduction type electron emission element using an In2O3/SnO2 thin film [M. Hartwell an C. G. Fonstad: xe2x80x9cIEEE Trans. ED Conf.xe2x80x9d, 519(1975)], a surface conduction type electron emission element using a carbon thin film [xe2x80x9cVapor Vacuum,xe2x80x9d Vol. 26, No. 1, p 22 (1983), by Hisashi Araki, et al.], etc.
As a typical example of those surface conduction type electron emission elements, a plan view of the above-mentioned element by M. Hartwell is shown in FIG. 93. In FIG. 93, reference numeral 8001 denotes a substrate, and reference numeral 8004 denotes an electrically conductive thin film that is made of a metal oxide formed through sputtering. The electrically conductive film 8004 is formed in an H-shaped plane as shown in FIG. 93. An electrifying process called xe2x80x9celectrification formingxe2x80x9d which will be described later is conducted on the electrically conductive thin film 8004 to form an electron emission portion 8005. In FIG. 93, an interval L is set to 0.5 to 1 (mm), and W is set to 0.1 (mm). For convenience of showing in the figure, the electron emission portion 8005 is shaped in a rectangle in the center of the electrically conductive thin film 8004. However, this shape is schematic and does not faithfully express the position and the configuration of the actual electron emission portion.
In the above-mentioned surface conduction type electron emission elements including the element proposed by M. Hartwell, et al., the electron emission portion 8005 is generally formed on the electrically conductive film 8004 through the electrifying process which is called xe2x80x9celectrification formingxe2x80x9d before the electron emission is conducted. In other words, the electrification forming is directed to a process in which a constant d.c. voltage or a d.c. voltage that steps up at a very slow rate such as about 1 V/min is applied to both ends of the electrically conductive film 8004 and electrified, to thereby locally destroy, deform or affect the electrically conductive film 8004, thus forming the electron emission portion 8005 which is in an electrically high-resistant state. A crack occurs in a part of the electrically conductive film 8004 which has been locally destroyed, deformed or affected. In the case where an appropriate voltage is applied to the electrically conductive thin film 8004 after the above electrification forming, electron emission is conducted from a portion close to the crack.
Examples of the FE type have been known from xe2x80x9cField Emissionxe2x80x9d of Advance in Electron Physics, 8, 89 (1956) by W. P. Dyke and W. W. Dolan, xe2x80x9cPhysical properties of thin-film field emission cathodes with molybdenum conesxe2x80x9d of J. Appl. Phys., 47,5248 (1976), by C. A. Spindt, etc.
As a typical example of the element structure of the FE element, FIG. 94 shows a cross-sectional view of the elements made by the above-mentioned C. A. Spindt, et al. In this figure, reference numeral 8010 denotes a substrate, 8011 is an emitter wiring made of an electrically conductive material, 8012 is an emitter cone, 8013 is an insulating layer, and 8014 is a gate electrode. The element of this type is so designed as to apply an appropriate voltage between the emitter cone 8012 and the gate electrode 8014 to produce electric field emission from a leading portion of the emitter cone 8012.
Also, as another element structure of the FE type, there is an example in which an emitter and a gate electrode are disposed on a substrate substantially in parallel with the substrate plane, without using a laminate structure shown in FIG. 94.
Also, as an example of the MIM type, there has been known, for example, xe2x80x9cOperation of tunnel-emission devices,xe2x80x9d J. Appl. Phys., 32,646 (1961) by C. A. Mead, etc. A typical example of the element structure of the MIM type is shown in FIG. 95. FIG. 95 is a cross-sectional view, and in the figure, reference numeral 8020 denotes a substrate, 8021 is a lower electrode made of metal, 8022 is a thin insulating layer about 10 nm in thickness, and 8023 is an upper electrode made of metal about 8 to 30 nm in thickness. In the MIM type, an appropriate voltage is applied between the upper electrode 8023 and the lower electrode 8021, to thereby produce electron emission from the surface of the upper electrode 8023.
The above-mentioned cold cathode element does not require a heater for heating because it can obtain electron emission at a low temperature as compared with the hot cathode element. Accordingly, the cold cathode element is simpler in structure than the hot cathode element and can prepare a fine element. Also, in the cold cathode element, even if a large number of elements are disposed on the substrate with a high density, a problem such as heat melting of the substrate is difficult to occur. Further, the cold cathode element is advantageous in that a response speed is high which is different from the hot cathode element which is low in the response speed because it operates due to heating by the heater. For the above-mentioned reasons, a study for applying the cold cathode elements has been extensively conducted.
For example, the surface conduction type electron emission element has the advantage that a large number of elements can be formed on a large area since it is particularly simple in structure and easy to manufacture among the cold cathode elements.
For that reason, a method in which a large number of elements are arranged and driven has been studied as disclosed in JP-A-64-31332 by the present applicant.
As the application of the surface conduction type electron emission element, for example, an image display device, an image forming apparatus such as an image recording device, a charge beam source, and so on have been studied.
In particular, as the application to the image display device, there has been studied an image display device using the combination of the surface conduction type electron emission element with a phosphor that emits light by irradiation of an electron beam as disclosed in for example U.S. Pat. No. 5,066,883 by the present applicant, JP-A-2-257551, and JP-A-4-28137. In the image display device using the combination of the surface conduction type electron emission element with the phosphor, the characteristic superior to the conventional other image display devices is expected. For example, even as compared with the liquid crystal display device which has been spreading in recent years, the above image display device is excellent in that no back light is required because it is of the self light emitting type and the angle of visibility is broad.
Also, a method in which a large number of FE type elements are disposed and driven is disclosed in, for example, U.S. Pat. No. 4,904,895 by the present applicant. Also, as an example of applying the FE type to the image display device, there has been known, for example, a plate type display device reported by R. Meyer [R. Meyer: xe2x80x9cRecent Development on Micro-tips Display at LETIxe2x80x9d, Tech. Digest of 4th Int. Vacuum Micro-electronics Conf., Nagahama, pp. 6 to 9 (1991].
Also, an example in which a large number of MIM type elements are arranged and applied to an image display device is disclosed in, for example, JP-A-3-55738 by the present applicant.
Among the image forming apparatuses using the above-mentioned electron emission element, attention has been paid to the flat type image display device thin in depthwise as a replacement of the CRT type image display device since the space is saved and the weight is light.
FIG. 96 is a perspective view showing an example of a display panel portion which forms a plane-type image display device, in which a part of the panel is cut off in order to show the internal structure.
In FIG. 96, reference numeral 8115 denotes a rear plate, 8116 a side wall, 8117 a face plate, and the rear plate 8115, the side wall 8116 and the face plate 8117 form an envelope (airtight vessel) for maintaining the interior of the display panel in a vacuum state.
The rear plate 8115 is fixed with a substrate 8111, and Nxc3x97M cold cathode elements 8112 are formed on the substrate 8111 (N and M are positive integers of equal to or larger than 2 or more and appropriately set in accordance with the target number of display pixels). Also, the Nxc3x97M cold cathode elements 8112 are wired by M row wirings 8113 and N column wirings 8114 as shown in FIG. 96. A portion made up of the substrate 8111, the cold cathode elements 8112, the row wirings 8113 and the column wirings 8114 is called the multiple electron beam source. Also, at least in portions where the row wirings 8113 and the column wirings 8114 cross each other, an insulating layer (not shown) between both of the wirings is formed to keep electric insulation.
A lower surface of the face plate 8117 is formed with a fluorescent film 8118 formed of a phosphor on which phosphors (not shown) of three primary colors consisting of red (R), green (G) and blue (B) are separately painted. Also, black material (not shown) are disposed between the respective color phosphors which form the fluorescent film 8118, and a metal back 8119 made of Al or the like is formed on a surface of the fluorescent film 8118 on the rear plate 8115 side.
Dx1 to Dxm, Dy1 to Dyn and Hv are electric connection terminals with an airtight structure provided for electrically connecting the display panel to an electric circuit not shown. Dx1 to Dxm are electrically connected to the row wirings 8113 of the multiple electron beam source, Dy1 to Dyn are electrically connected to the column wirings 8114 of the multiple electron beam source, and Hv is electrically connected to the metal back 8119, respectively.
Also, the interior of the above airtight vessel is maintained in a vacuum state of about 1xc3x9710xe2x88x924 Pa, and there is required means for preventing the deformation or destruction of the rear plate 8115 and the face plate 8117 due to a pressure difference between the interior of the airtight vessel and the external, as a display area of the image display device increases. In a method of thickening the rear plate 8115 and the face plate 8117, not only does the weight of the image display device increase, but also a distortion of an image or a parallax occurs when viewing the display device from an oblique direction. On the contrary, in FIG. 96, there is provided a structure support (called spacer or rib) 8120 which is formed of a relatively thin glass substrate for supporting the atmospheric pressure. With this structure, a space of normally sub mm to several mm is kept between the substrate 8111 on which the multiple beam electron source is formed and the face plate 8117 on which the fluorescent film 8118 is formed, and the interior of the airtight vessel is maintained in a high vacuum state as described above.
In the image display device using the display panel as described above, when a voltage is applied to the respective cold cathode elements 8112 through the vessel external terminals Dx1 to Dxm and Dy1 to Dyn, electrons are emitted from the respective cold cathode elements 8112. At the same time, with the application of a high voltage of several hundreds (V) to several (kV) to the metal back 8119 through the vessel external terminal Hv, the above emitted electrons are accelerated and allowed to collide with an inner surface of the face plate 8117. As a result, the phosphors of the respective colors which form the fluorescent film 8118 are excited and emit light, thus displaying an image.
In general, electrons emitted from the electron source are accelerated by a voltage (accelerating voltage) applied between the electron source and the phosphor and collide with the phosphor to emit a light. Accordingly, a display image becomes higher in luminance as the accelerating voltage is larger. However, as described above, in a case of a thin-type image forming apparatus in which an opposite distance between the electron source and a substrate having the phosphor is shortened, an electric field intensity formed between the electron source and the phosphor becomes large due to the accelerating voltage.
The above case suffers from the following problems.
In the case where a high electric field is applied to the electron source, specifically, a high voltage of several hundreds V or higher (that is, a high electric field of 1 kV/mm or higher)) is applied between the multiple beam electron source and the face plate 8117 in order to accelerate the emitted electrons from the cold cathode element 8112, and for example, foreign material such as dust, a protrusion or the like (hereinafter generically named protrusion) exists on the electron source. There is a case where the electric field concentrates to the protrusion, and the electrons are emitted therefrom. The configuration of the protrusion further becomes sharp due to an influence of a heat caused by the emitted current or of the high electric field, the electric field intensity becomes further higher, and the amount of emitted electrons increases.
When a positive feedback is effected as described above, there finally occurs such a phenomenon that the projection is thermally destroyed.
When the above phenomenon occurs as described above, not only the protrusion is destroyed but also the vacuum atmosphere within the image forming apparatus is deteriorated. This acts as a trigger and a discharge phenomenon occurs between the electron source and the phosphor to which the high electric field is applied. The accelerated cations collide with the electron source to damage the electron source, resulting in such a problem that an image defect is induced.
As a method of suppressing the above discharge phenomenon, there has been known, for example, a method in which, in order to suppress spark discharge, the spark discharge is conducted in a high vacuum in advance (for example, xe2x80x9chigh voltage technologyxe2x80x9d (Electric Institute, Ohm Company 1981)). The above processing is usually called xe2x80x9cconditioningxe2x80x9d.
In manufacturing a large-area image forming apparatus, there is a case in which the execution of the conditioning process adversely affects the electron emission characteristic. This is because the Joule heat consumed in the element by discharge during the conditioning process destroys the electrically conductive thin film.
FIG. 26 is a diagram showing an equivalent circuit in this process. It is presumed that the above phenomenon is induced by electric charges which are stored in a capacitor made up of an electron source substrate 2071 and an electrode 2010 for high voltage application which conduct the conditioning process.
When a voltage V is applied across a parallel plate capacitor formed of two electrodes each having an area S which are apart from each other at a distance d, the stored electric charge amount Q is represented by Q=CV=∈SV/d. When the same electric field is developed in the conditioning process, an energy E stored in the capacitor made up of the electron source substrate 2071 and the electrode 2010 for high voltage application is represented by E=CV/2=∈SV/2d where ∈ is the dielectric constant of a material between those two electrodes (or vacuum).
For that reason, when the conditioning process is conducted by using the electron source substrate 2071 and the electrode 2010 for high voltage application which is opposite to the electron source substrate 2071 and identical in area, there arises such a problem that the energy consumed by the electron source substrate during the discharge operation increases in proportion to the area.
Also, as another method of suppressing the above discharge phenomenon, there is disclosed in JP-A-8-106847 a technique in which an inductor is disposed between an anode and an external voltage source for the purpose of limiting a large current that flows in an emitter (cathode) as an electric arc through the anode from the external voltage source during arc discharge operation when the arc discharge occurs. In the present specification, the abnormal discharge includes the above-described arc discharge.
The outline of the technique disclosed in the above-described JP-A-8-106847 is schematically shown in FIG. 97. In FIG. 97, reference numeral 9121 denotes a substrate; 9122 is a cathode electrode; 9123 is an emitter; 9124 is a cathode conductor; 9125 is an insulator; 9126 is a gate; 9127 is an anode; 9128 is an inductor; 9129 is a resistor; and 9130 is a voltage source. The technique is that an electric field emission element is used as the electron emission element, and a current which is concerned in the arc discharge between the anode 9127 and the emitter 9123 and supplied from a voltage source 9130 is substantially limited by the provision of the inductor 9128 while the arc discharge occurs between the anode 9127 and the emitter 9123 (cathode). In other words, in the case where the arc discharge occurs and the potential of the anode is lowered, the implantation of electric charges from the external power supply is temporally limited.
However, the large-screen image forming apparatus large in a capacitance between the anode and the cathode electrode suffers from such a problem that the amount of electric charges stored in the anode and the cathode electrode is large, and the electric charges move through a discharge path in response to the deterioration of the potential of the anode when the abnormal discharge starts. In the case where the movement of the electric charges is conducted in a moment, a current value becomes remarkably large. It is needless to say that the current cannot be observed as a current that flows into the anode from the external power supply, that is, the current cannot be suppressed in the above-described method of limiting the implantation of the electric charges from the external power supply.
This is because in the case where the abnormal discharge occurs, the lowered potential of the anode is restored, in other words, only a current that charges the capacitor made up of the anode and the cathode substrate, or a current that connects the arc as a result of the arc discharge is observed. The present inventors have recognized through the measurement of a change in the anode potential with a time during the abnormal discharge that the movement of the electric charges in response to the deterioration of the potential of the anode occurs by a time scale of about xcexc seconds or shorter. Also, the present inventors have recognized that the current corresponding to the drop of the potential of the anode may induce a damage because it flows through the discharge path. Accordingly, in implementation of the conditioning process, it becomes necessary to suppress the current corresponding to the drop of the potential of the anode from flowing through the discharge path.
Also, once the abnormal discharge occurs, there is the possibility that a secondary abnormal discharge occurs, and it is important to prevent the secondary abnormal discharge. It is necessary to surely prevent the secondary abnormal discharge when the secondary abnormal discharge occurs in a linking manner, because there may be a case where a large damage resultantly occurs even if no damage occurs in the first abnormal discharge.
An object of the present invention is to provide a manufacturing method that removes a factor such as a protrusion which induces a discharge phenomenon within an electron beam device represented by an image forming apparatus, to thereby manufacture an excellent electron beam device (electron source) which is high in reliability through the manufacturing method, and to provide an image forming apparatus with no defective pixel even in image display for a long period of time.
Also, another object of the present invention is to provide a manufacturing method and a manufacturing apparatus for an image forming apparatus which suppress a damage caused by abnormal discharge and prevent abnormal discharge which may secondarily occur as much as possible.
According to the present invention, there is provided a method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming the wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the wiring is formed is conducted after the wiring forming step is completed and before the electron emission portion forming process is completed.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field is 1 kV/mm or more in its electric field intensity.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying steps comprises a step of discharging, by application of the electric field, electricity from a portion of the substrate from which electricity is liable to be discharged in various processes after the electric field applying process including the electron emission portion forming process, or when the electron beam device is used, to thereby change the portion into a shape which is difficult to discharge electricity.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with the respective electron emission portions, and the electric field applying step is conducted before the electrode forming step is conducted.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the pair of electrode comprise a pair of electrodes that constitute surface conduction type electron emission elements.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electrode forming step comprises a step which includes a thin film forming step of forming an electrically conductive thin film on the substrate, and produces a gap in the formed electrically conductive thin film and constitutes the pair of electrodes by the electrically conductive thin films which exists on both sides of the gap.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying step is conducted before the thin film forming step is conducted.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying step is conducted after the thin film forming step is completed and before the gap is produced in the electrically conductive thin film.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the pair of electrodes comprise an emitter and a gate of the electric field emission type electron emission element.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field emission type electron emission element comprises the emitter that emits electrons from an end portion and the gate that produces an electric field between the end portion and the gate.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying step is conducted before the emitter is formed.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying step is conducted before the gate is formed.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the plurality of electron emission portions are connected onto one main surface of the substrate in the form of a ladder or a matrix by the wirings.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, in the electric field applying step, an electrode is disposed opposite to a surface of the substrate on which the wirings are disposed, and a voltage is applied between the electrode and the wirings on the substrate to apply the electric field.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, a voltage given between the electrode and the wirings is changed during the electric field applying step.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, a distance between the electrode and the substrate is changed during the electric field applying step.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, a current limit resistor is connected between the electrode and the power supply that applies a voltage to the electrode.
In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying step is conducted in a vacuum atmosphere.
According to the present invention, there is provided a method of manufacturing an image forming apparatus that includes an electron source in which a plurality of electron source elements each having a pair of element electrodes formed on a substrate, an electrically conductive thin film which are electrically connected to each of the element electrodes, and an electron emission portion formed on a part of the electrically conductive thin film are formed on the same substrate, and the element electrodes of the respective electron source elements are connected in the form of a ladder or a matrix by wirings; and an image forming member disposed opposite to the electron source on the substrate, the method comprising: an electric field applying step of applying a given electric field to the substrate on which the wirings are formed after a step of forming the wirings is completed and before a step of forming the electron emission portions is completed.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, a control electrode which controls the electron beam emitted from the respective electron source elements in response to an information signal is combined.
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, the electric field applying step is conducted in such a manner that the electrode for applying the electric field and the substrate are disposed opposite to each other to apply a voltage between the electrode and the wirings, and an energy stored in the capacitor formed of the electrode and the substrate is equal to or less than an energy that destroys the electrically conductive thin film.
According to the present invention, there is provided a method of manufacturing an electron beam device that includes a plurality of surface conduction type electron emission elements, the method comprising a step of forming plural pairs of element electrodes on a substrate, a step of connecting a plurality of row-directional wirings and a plurality of column-directional wirings which are stacked one on another through an insulating layer to the respective electrodes of the plural pairs of element electrodes to form common wirings in a matrix, a step of forming electrically conductive thin films between each pair of element electrodes, a forming step of forming electron emission portions by conducting an electrifying process on the electrically conductive thin films between each pair of element electrodes, and a conditioning step of applying the electric field by applying a voltage between the electrode and the common wiring in which an electrode for applying an electric field to a surface having the common wirings and the substrate are disposed opposite to each other, wherein the conditioning step is conducted under the condition where an energy stored in a capacitor formed of the electrode and the substrate is equal to or less than an energy that destroys the electrically conductive thin film.
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, assuming that an area where the electrode and the substrate face each other is S, a distance between the electrode and the substrate is Hc, a voltage applied between the electrode and the common wiring is Vc, a dielectric constant of vacuum is ∈, and an energy by which the electrically conductive thin film is destroyed is Eth, the conditioning step is conducted under the following condition:
∈xc3x97Sxc3x97Vc2/2Hc less than Ethxe2x80x83xe2x80x83(1)
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, a plurality of electrodes for applying the electric field are used in the conditioning step.
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, a relative position between the electrode and the substrate is changed in the conditioning step.
According to the present invention, there is provided a method of manufacturing an image forming apparatus that includes a substrate on which a plurality of surface conduction type electron emission elements are formed, and an image forming member which is disposed opposite to the surface conduction type electron emission elements on the substrate, the method comprising a step of forming plural pairs of element electrodes on a substrate, a step of connecting a plurality of row-directional wirings and a plurality of column-directional wirings which are stacked one on another through an insulating layer to the respective electrodes of the plural pairs of element electrodes to form common wirings in a matrix, a step of forming electrically conductive thin films between each pair of element electrodes, a forming step of forming electron emission portions by conducting an electrifying process on the electrically conductive thin films between each pair of element electrodes, and a conditioning step of applying the electric field by applying a voltage between the electrode and the common wiring in which an electrode for applying an electric field to a surface having the common wirings and the substrate are disposed opposite to each other, wherein the conditioning step is conducted under the condition where an energy stored in a capacitor formed of the electrode and the substrate is equal to or less than an energy that destroys the electrically conductive thin film.
According to the present invention, there is provided a method of manufacturing an electron beam device that includes a first plate with an electron beam source which generates an electron beam, the method comprising a step of applying a voltage between the first plate and an electrode which is opposite to the first plate, wherein in the step, a voltage that allows a leader current to flow is applied between the first plate and an electrode which is opposite to the first plate.
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, the voltage is a voltage which can maintain a state in which the leader current flows.
According to the present invention, there is provided a method of manufacturing an electron beam device that includes a first plate with an electron beam source which is formed of an electrically conductive film and generates an electron beam, the method comprising a step of applying a voltage between the first plate and an electrode which is opposite to the first plate, wherein in the step, a voltage an influence of which on the electrically conductive film can be permitted is applied.
According to the present invention, there is provided a method of manufacturing an image forming apparatus that includes a rear plate on which an electron beam source is formed and a face plate on which a phosphor that emits a light by irradiation of an electron beam is formed, the method comprising a step of applying a high voltage to a substrate on which an electrode is formed before a vacuum vessel including the rear plate and the face plate therein is formed.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage applying step is conducted on a rear plate substrate on which the electrode is formed before an electron beam source is completed.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage applying step is conducted in vacuum.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage applying step is conducted in gas.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, a high voltage is applied between the substrate on which the electrode is formed and a dummy face plate with a counter electrode.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the substrate on which the electrode is formed has a feeder wiring to the electron emission element, and the high voltage is applied with the wiring as one electrode and the dummy face plate as the other electrode.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the substrate on which the electrode is formed has a plurality of row-directional wirings and a plurality of column-directional elements for feeder so as to wire a plurality of electron emission elements in a matrix, all of the row-directional wirings and the column-directional wirings are made common wiring to the electron emission element, and the high voltage is applied with the row-directional and column-directional wirings as one electrode and the dummy face plate as the other electrode.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage is a d.c. voltage that gradually steps up from a low voltage.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage is an a.c. voltage that gradually steps up from a low voltage.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage is a pulse voltage that gradually steps up from a low voltage.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the electron beam source is a cold cathode element.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the electron beam source is a surface conduction type emission element.
According to the present invention, there is provided a method of manufacturing an image forming apparatus that includes a rear plate with an electron beam source, a face plate on which a phosphor that emits a light by irradiation of an electron beam is formed, and a structure support disposed between the rear plate and the face plate, the method comprising a step of applying a high voltage between the face plate and the rear plated after the face plate, the rear plate and the structure support are assembled together into a panel, and a step of forming an electron source after the high voltage applying step.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage applying step is conducted in vacuum.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage applying step is conducted by introducing gas within the image forming apparatus.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the electron beam source has a plurality of electron emission elements connected to each other by a plurality of wirings, and in the high voltage applying step, the plurality of wirings are commonly grounded, and the high voltage is applied to the face plate.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the structure support has a rectangular shape and is disposed between the electron beam source and the face plate so that its longitudinal direction is in parallel with the plurality of wirings.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the electron source has a plurality of electron emission elements which are wired in a matrix by a plurality of row-directional wiring and a plurality of column-directional wirings, and in the high voltage applying step, the plurality of row-directional wirings and the plurality of column-directional wirings are commonly grounded, and the high voltage is applied to the face plate.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the structure support is disposed between the electron beam source and the face plate so that its longitudinal direction is in parallel with any one of the plurality of row-directional wirings and the plurality of column-directional wirings.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage is an a.c. voltage a peak value of which gradually steps up from a low voltage.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage is a pulse voltage a peak value of which gradually steps up from a low voltage.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the high voltage is a monotonic increase voltage which gradually steps up from a low voltage.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the electron beam source is a cold cathode element.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the electron beam source is a surface conduction type emission element.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the electron source forming step includes an electrification forming step.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the electron source forming step includes an electrification activating step.
According to the present invention, there is provided a method of manufacturing an electron beam device that includes a first plate with an electron beam source which generates an electron beam and an electrode which is opposite to the first plate, the method comprising a first step of applying a voltage between the first plate and the electrode, and a step of forming the electron beam source after the first step.
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, the electron beam source forming step conducted after the first step comprises a step of forming a high resistant portion on an electrically conductive film by electrifying the electrically conductive film.
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, the electron beam source forming step after the first step comprises a step of depositing a deposit on an electron emission portion, a portion close to the electron emission portion or the electron emission portion, the portion close to the electron emission portion.
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, the first step is conducted after wirings are formed on the first plate.
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, the first step is conducted after an electrically conductive thin film in which the electron emission portion is formed is formed.
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, a current flows between the first plate and the electrode by applying a voltage between the first plate and the electrode.
In one mode of the method of manufacturing an electron beam device in accordance with the present invention, a current flows by discharge generated between the first plate and the electrode.
According to the present invention, there is provided a method of manufacturing an image forming apparatus including a conditioning step of disposing an electrode at a position opposite to an electron source substrate that constitutes an electron source and applying a high voltage between the electrode and an electron source substrate in a step of manufacturing the electron source that constitutes an image forming apparatus, the method comprising plural kinds of conditioning steps where the sheet resistances of the electrodes are different, respectively.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, a high voltage is applied between the electron source substrate and the electrode with the electron source substrate side as a cathode.
According to the present invention, there is provided a method of manufacturing an image forming apparatus including a conditioning step of disposing an electrode at a position opposite to an anode substrate that constitutes an anode and applying a high voltage between the electrode and an anode substrate in a step of manufacturing the anode that constitutes an image forming apparatus, the method comprising plural kinds of conditioning steps where the sheet resistances of the electrodes are different, respectively.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, a high voltage is applied between the anode substrate and the electrode with the substrate side as an anode.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, there are provided a fluorescent film forming step of forming a fluorescent film that emits a light by allowing electrons to collide with the anode substrate; a first conditioning step which is conducted after the fluorescent film forming step; and a second conditioning step which is conducted by the electrode which is smaller in sheet resistance than that in the first conditioning step conducted after the first conditioning step.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, there are provided conditioning steps in which the electric field intensities formed between the substrate and the electrode are different, respectively.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, at least one of a voltage value which is applied to the electrode or a distance between the substrate and the electrode is changed to make the electric field intensities different, respectively.
According to the present invention, there is provided a method of manufacturing a plate type image forming apparatus that includes a cathode substrate on which an electron beam source is disposed, and an image formation anode substrate disposed opposite to the cathode substrate, wherein a high voltage is applied to an anode disposed opposite to the cathode substrate with the cathode substrate as a cathode, and abnormal discharge generated by application of the high voltage is detected to suppress the abnormal discharge during manufacturing of the cathode substrate.
According to the present invention, there is provided a method of manufacturing a plate type image forming apparatus that includes a cathode substrate on which an electron beam source is disposed, and an image formation anode substrate disposed opposite to the cathode substrate, wherein a high voltage is applied to an anode disposed opposite to the cathode substrate with the cathode substrate as a cathode, and abnormal discharge generated by application of the high voltage is detected, and the potential the anode is allowed to approach the potential of the cathode to suppress the abnormal discharge during manufacturing of the cathode substrate.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the abnormal discharge is detected to electrically cut off the anode and the high voltage power supply connected to the anode.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the cathode substrate is that a plurality of surface conduction type electron emission elements are disposed in a matrix as the electron source.
According to the present invention, there is provided a device for manufacturing a plate type image forming apparatus including a cathode substrate on which an electron beam source is disposed, and an image formation anode substrate disposed opposite to the cathode substrate, the device comprising an anode, a high voltage power supply connected to the anode, and detecting means for detecting abnormal discharge generated between the anode and a cathode disposed opposite to the anode by application of a high voltage from the high voltage power supply, wherein the high voltage is applied between the cathode substrate disposed as the cathode and the anode by the high voltage power supply, and the generated abnormal discharge is detected by the detecting means to suppress the abnormal discharge during manufacturing of the cathode substrate.
According to the present invention, there is provided a device for manufacturing a plate type image forming apparatus including a cathode substrate on which an electron beam source is disposed, and an image formation anode substrate disposed opposite to the cathode substrate, the device comprising an anode, a high voltage power supply connected to the anode, and detecting means for detecting abnormal discharge generated between the anode and a cathode disposed opposite to the anode by application of a high voltage from the high voltage power supply, wherein the high voltage is applied between the cathode substrate disposed as the cathode and the anode by the high voltage power supply, and the generated abnormal discharge is detected by the detecting means, and the potential of the anode is allowed to approach the potential of the cathode to suppress the abnormal discharge during manufacturing of the cathode substrate.
In one mode of the device for manufacturing an image forming apparatus in accordance with the present invention, there is provided means for electrically cutting off the anode and the high voltage power supply connected to the anode on the basis of the detection of the abnormal discharge by the detecting means in one mode of the device of manufacturing an image forming apparatus in accordance with the present invention, the cathode substrate is that a plurality of surface conduction type electron emission elements are disposed in a matrix as the electron source.
An electron beam device according to the present invention is manufactured through the above-mentioned manufacturing method.
An image forming apparatus according to the present invention is manufactured through the above-mentioned manufacturing method.
According to the present invention, there is provided a method of manufacturing an electron source having a plurality of electron emission elements and wirings connected to the electron emission elements on a substrate, in which each of the electron emission elements includes a pair of opposite electrodes disposed on the substrate, an electrically conductive film connected to the electrodes and having a first crack in a region between the electrodes, and a deposit mainly containing carbon, having a second crack narrower than the first crack within the first crack and disposed within the first crack and in the region of the electrically conductive film including the first crack, the method comprising the steps of forming the electrically conductive film, forming the first crack in the electrically conductive film (forming step), forming the deposit mainly containing carbon (activating step), the activating step being conducted after the forming step, and applying an electric field in a direction substantially perpendicular to a surface of the substrate on which at least the wirings and the electrodes are formed where the electron emission elements are formed (conditioning step), wherein the conditioning step is executed before the forming step.
In one mode of the method of manufacturing an electron source in accordance with the present invention, the conditioning step is conducted by disposing a conditioning electrode opposite to a surface of the substrate on which the electrodes and the wirings are formed at an interval and applying a voltage between the conditioning electrode and the substrate.
In one mode of the method of manufacturing an electron source in accordance with the present invention, the conditioning step is conducted after the step of forming the wirings and the electrodes on the substrate, and thereafter the step of forming the electrically conductive film is conducted.
In one mode of the method of manufacturing an electron source in accordance with the present invention, the conditioning step comprises a first conditioning step conducted after the step of forming the wirings and the electrodes on the substrate and before the electrically conductive film forming step, and a second conditioning step conducted after the electrically conductive film forming step and before the forming step, wherein assuming that the sheet resistances of the conditioning electrode when conducting the first and second conditioning steps are R1 and R2, respectively, the values R1 and R2 satisfy R1 less than R2.
In one mode of the method of manufacturing an electron source in accordance with the present invention, there is provided, after the forming step and before the activating step, a third conditioning step of disposing the conditioning electrode opposite to a surface of the substrate on which the electrodes and the wirings are formed at an interval and applying a voltage between the conditioning electrode and the substrate to apply an electric field in direction substantially perpendicular to the surface of the substrate on which the electron emission elements are formed, wherein the sheet resistance R3 of the conditioning electrode satisfies R2 less than R3.
In one mode of the method of manufacturing an electron source in accordance with the present invention, there is provided, after the activating step, a fourth conditioning step of disposing the conditioning electrode opposite to a surface of the substrate on which the electrodes and the wirings are formed at an interval and applying a voltage between the conditioning electrode and the substrate to apply an electric field in a direction substantially perpendicular to the surface of the substrate on which the electron emission elements are formed, wherein the sheet resistance R4 of the conditioning electrode satisfies R4 less than R1.
In one mode of the method of manufacturing an electron source in accordance with the present invention, the conditioning step is executed while a leader phenomenon of the discharge between the conditioning electrode and the substrate is monitored, and control under which the potential of the conditioning electrode is allowed to approach the potential of the substrate is conducted when the leader phenomenon is detected.
In one mode of the method of manufacturing an electron source in accordance with the present invention, the conditioning step is executed while voltage supply means is connected between the conditioning electrode and the substrate, a leader phenomenon of the discharge between the conditioning electrode and the substrate is monitored, and control for cutting off the connection between the conditioning electrode and the voltage applying means is conducted when the leader phenomenon is detected.
In one mode of the method of manufacturing an electron source in accordance with the present invention, the conditioning step is executed by moving the conditioning electrode on the substrate while an interval between the conditioning electrode and the substrate is held to a given value by using the conditioning electrode having an area opposite to the substrate which is smaller than an area of the surface of the substrate on which the electron emission elements are disposed.
In one mode of the method of manufacturing an electron source in accordance with the present invention, the conditioning step is executed while an interval between the conditioning electrode and the substrate is changed.
According to the present invention, there is provided a method of manufacturing an image forming apparatus including an electron source having a plurality of electron emission elements and wirings connected to the electron emission elements and an image forming member which forms an image by irradiation of an electron beam emitted from the electron source on a substrate, the electron source and the image forming member being disposed opposite to each other within an airtight vessel, in which the electron emission elements includes a pair of opposite electrodes disposed on the substrate, an electrically conductive film connected to the electrodes and having a first crack in a region between the electrodes, and a deposit mainly containing carbon, having a second crack narrower than the first crack within the first crack and disposed within the first crack and in the region of the electrically conductive film including the first crack, the method comprising the steps of: forming the wiring and the electrode on the substrate; forming the electrically conductive film; forming the first crack in the electrically conductive film (forming step); forming the deposit mainly containing the carbon (activating step), the relevant step being conducted after the forming step; and
applying an electric field in a direction substantially perpendicular to a surface of the substrate on which at least the wirings and the electrodes are formed where the electron emission elements are formed (conditioning step); and
assembling the airtight vessel so as to include the electron source and the image forming apparatus therein;
wherein the conditioning step is executed by applying a voltage between the image forming member and the substrate after the step of assembling the airtight vessel and before the forming step.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the conditioning step is executed while a leader phenomenon of the discharge between the image forming member and the substrate is monitored, and control under which the potential of the image forming member is allowed to approach the potential of the substrate is conducted when the leader phenomenon is detected.
In one mode of the method of manufacturing an image forming apparatus in accordance with the present invention, the conditioning step is executed while voltage supply means is connected between the image forming member and the substrate, a leader phenomenon of the discharge between the image forming member and the substrate is monitored, and control for cutting off the connection between the image forming member and the voltage applying means is conducted when the leader phenomenon is detected.
According to the present invention, there is provided a manufacturing apparatus for executing the electron source manufacturing method, wherein an area of the conditioning electrode opposite to the substrate is smaller than an area of the surface of the substrate which includes the electron emission elements, and there is provided moving means for moving the conditioning electrode while an interval between the conditioning electrode and the substrate is held to a given value.
In one mode of the manufacturing method in accordance with the present invention, there is provided interval control means for controlling the interval between the conditioning electrode and the substrate in the conditioning step.
According to the present invention, there is provided a manufacturing apparatus for executing the electron source manufacturing method, in which there are provided monitoring means for monitoring a leader phenomenon of the discharge between the conditioning electrode and the substrate; and potential changing means for making the potential of the conditioning electrode approach the potential of the substrate on the basis of a signal indicating that the monitoring means detects the leader phenomenon.
In one mode of the manufacturing apparatus in accordance with the present invention, the potential changing means comprises a switch for turning on/off a circuit that short-circuits between the conditioning electrode and the substrate.
According to the present invention, there is provided a manufacturing apparatus for executing the image forming apparatus manufacturing method, in which there are provided monitoring means for monitoring a leader phenomenon of the discharge between the image forming member and the substrate, and potential changing means for making the potential of the image forming member approach the potential of the substrate on the basis of a signal indicating that the monitoring means detects the leader phenomenon.
In one mode of the manufacturing apparatus in accordance with the present invention, the potential changing means comprises a switch for turning on/off a circuit that short-circuits between the image forming member and the substrate.
According to the present invention, there is provided a manufacturing apparatus for executing the electron source manufacturing method, in which there are provided monitoring means for monitoring a leader phenomenon of the discharge between the conditioning electrode and the substrate, and connection cutoff means for cutting off the electric connection between the conditioning electrode and the voltage applying device on the basis of a signal indicating that the monitoring means detects the leader phenomenon.
According to the present invention, there is provided a manufacturing apparatus for executing the image forming apparatus manufacturing method, in which there are provided monitoring means for monitoring a leader phenomenon of the discharge between the image forming member and the substrate, and connection cutoff means for cutting off the electric connection between the image forming member and the voltage applying device on the basis of a signal indicating that the monitoring means detects the leader phenomenon.